Abstract

The extra-cranial venous system is complex and not well studied in comparison to the
peripheral venous system. A newly proposed vascular condition, named chronic cerebrospinal
venous insufficiency (CCSVI), described initially in patients with multiple sclerosis
(MS) has triggered intense interest in better understanding of the role of extra-cranial
venous anomalies and developmental variants. So far, there is no established diagnostic
imaging modality, non-invasive or invasive, that can serve as the “gold standard”
for detection of these venous anomalies. However, consensus guidelines and standardized
imaging protocols are emerging. Most likely, a multimodal imaging approach will ultimately
be the most comprehensive means for screening, diagnostic and monitoring purposes.
Further research is needed to determine the spectrum of extra-cranial venous pathology
and to compare the imaging findings with pathological examinations. The ability to
define and reliably detect noninvasively these anomalies is an essential step toward
establishing their incidence and prevalence. The role for these anomalies in causing
significant hemodynamic consequences for the intra-cranial venous drainage in MS patients
and other neurologic disorders, and in aging, remains unproven.